While secret societies have terrific members-only benefits, their guerilla-centric initiation rites are often illegal. Make a solemn fitness vow that's legal with today's Groupon: for $30, you get a one-month membership along with three personal-training sessions and 100 minutes of tanning (up to a $169 value) at Sioux Empire Fitness on Tennis Lane. This deal is good for new members only and you must be 18 or older.

Sioux Empire Fitness's full-service gym offers members a variety of group-exercise classes and facilities for swimming, basketball, volleyball, and more. Your one-month membership (a $57 value) grants you access to all of these amenities. Physical-fitness dreams come true in this multi-recreational facility, whether you're sprinting down the indoor track while pursued by imaginary bulls or freestyling in the swimming pool with a floating replica of Abraham Lincoln. Total-body fitness waits inside a full-size indoor basketball court and on two sand volleyball courts. Work out solo on cardio equipment in the fitness area, or try a group-fitness class such as aqua aerobics or yoga, all of which run on a flexible schedule. This deal also gets you three personal- training sessions to streamline your soul-sack (up to an $87 value) and 100 minutes of tanning (a $25 value) to bronze your newly fit body for mantle placement.

A variety of equipment and programs at Sioux Empire Fitness reduces workout boredom while eliminating fat and flab. Membership grants access to additional services at the gym, such as a free childcare facility for kids aged three months to 10 years. Keep wee ones playing happily while you tone up or unwind in the dry sauna or whirlpool. Get back on the exercise horse or give it a swift kick in the torso with today's Groupon to Sioux Empire Fitness.

Use of tennis and racquetball courts costs extra.